// SPDX-FileCopyrightText: 2025 The Project Pterodactyl Developers
//
// SPDX-License-Identifier: MPL-2.0

import Foundation

enum Declaration: Grammar {
	enum Kinds {
		static let claim = SyntaxTreeKind(name: "decl.claim")
		static let refine = SyntaxTreeKind(name: "decl.refine")
		static let define = SyntaxTreeKind(name: "decl.define")
	}

	static let kinds = [Kinds.claim, Kinds.refine, Kinds.define]
	
	static func before(_ parser: inout Parser) -> Bool {
		Lhs.before(&parser)
	}

	static let punctuationMap: [Punctuation: SyntaxTreeKind] = [
		.colon: Kinds.claim,
		.doubleLeftArrow: Kinds.refine,
		.doubleRightArrow: Kinds.define
	]

	static func inside(_ parser: inout Parser) -> ParseResult {
		Lhs.parse(&parser)
		parser.eatTrivia()

		var kind: SyntaxTreeKind = .error
		for cell in punctuationMap {
			if parser.eat(kind: .punctuation(cell.key), metadata: TokenMetadata(semanticTokenType: .operator)) {
				kind = cell.value
				break
			}
		}

		if kind == .error {
			parser.advance(error: "Expected one of \(punctuationMap.keys.map(\.rawValue)) in declaration")
		}

		parser.eatTrivia()
		Rhs.parse(&parser)

		return ParseResult(kind: kind)
	}
}

extension SyntaxView<Declaration> {
	var lhs: SyntaxView<Lhs>? { matchingSubview() }
	var rhs: SyntaxView<Rhs>? { matchingSubview() }
}